Real-time location and presence using a push-location client and server

ABSTRACT

A system for providing real-time always-on location is presented for maintaining the current location of a mobile device, while saving the battery by managing the GPS in a power-saving mode while the device is considered to be stationary. The system also provides a real-time location in an indoor environment where a GPS signal may not be available. Additionally, methods for driving detection are also presented.

CROSS REFERENCE TO RELATED APPLICATIONS

This application is a continuation of, and claims priority to, U.S.patent application Ser. No. 13/923,722, filed on Jun. 21, 2013, which isa continuation of U.S. patent application Ser. No. 12/728,216, filed onMar. 20, 2010 (issued as U.S. Pat. No. 8,489,111 on Jul. 16, 2013),which claims the benefit of U.S. Provisional Application Ser. No.61/162,263, filed on Mar. 21, 2009, and is a continuation-in-part ofU.S. patent application Ser. No. 11/838,876 filed on Aug. 14, 2007(issued as U.S. Pat. No. 8,050,690 on Nov. 1, 2011). The subject matterof these earlier filed applications is hereby incorporated by referencein its entirety.

BACKGROUND

Location based services (LBS) targeted for consumers and enterpriseapplications have started gaining acceptance by the industry.

With the advancements in Global Positioning System (GPS) technology formobile devices, the accuracy of mobile positioning systems has improvedsignificantly, and consumer LBS applications such as mapping, localsearch, and real-time navigation are now available from mobile carriersand several other companies.

However, the ability to determine and to constantly maintain a current,real-time location is still not available on mobile devices, and mobilepositioning systems and location based applications continue to rely ona pull or request based system, where an application or the systemqueries and gets a precise current location when it is required andrequested.

In case of real-time applications such as turn-by-turn navigation, thecurrent location is determined in real-time by requesting the locationrepeatedly and in frequent timing intervals for the duration such anapplication is in use.

However, such a pull or request based system does not maintain a precisecurrent location of device at all times, and doing that in real-timeimposes a significant drain of battery resources of the mobile device aswell as imposes significant computing costs for the mobile positioningsystem.

Even in case of an E-911 scenario, if a device shuts down in anunforeseen event or a mishap, a precise current location may not beavailable, and only an approximate location of a user may be availablefor emergence response purposes. In such events, mobile carriers candetermine an approximate location of the user based on cell-ID, however,a precise current or last known location that can only be determined byquerying the device using a GPS or A-GPS solution, which may not beavailable if the device has already shut down.

In summary, to optimize the computing resources, the mobile positioningsystem operates as a pull or request based system, and a preciselocation is only determined when an application requests it. Forapplications where a precise and current location of a user is requiredat all times, the mobile positioning system must repeatedly query thedevice in order to maintain a current, real-time location of the user.With state of the art techniques, an application can specify thefrequency or timing intervals of such requests, and can offload thisprocess to another middleware service provider, which can notify thesubscribing application(s) when the location changes. However, in orderto maintain a precise, current location at all times, the GPS or A-GPSchipset embedded in the device has to be regularly polled, and thebattery consumption continues to be a major constraint in enabling suchreal-time applications.

SUMMARY

In instances such as in an emergency response scenario or in a real-timelocation or presence application, where a current location of the mobiledevice is required in real-time, one aspect of the present invention isto provide such information using a push-based method without repeatedlysending location requests from the application(s) or the mobilepositioning system.

For most mobile users, the typical location versus time graph is suchthat for a good part of the day, the user is stationary at selectedlocations such as home or work, and only during a small part of the daythey are either mobile or at other locations. One aspect of the presentinvention is to manage the power saving modes of the embedded GPS orA-GPS chipset in the device such that while the device is stationary asdetermined by an accelerometer embedded in the device or by otheractivity detection methods in the operating system, the GPS or A-GPSchipset is set in a power saving mode.

Another aspect of the present invention is that while the device isdetermined to be stationary at a pre-determined location, one of thepower saving modes of the embedded GPS or A-GPS system in the device issuch that much of the power consuming circuits are shut down, and onlythe receive circuitry is put into the standby mode. Periodically, thereceive signals are monitored, and only if there is a threshold change,the embedded system is re-started and the location recomputed.

In another aspect of the present invention, the frequency of locationrequests are set based on the speed of the mobile device, so that whenthe user is stationary, the embedded GPS or A-GPS chipset is put in thepower saving mode for longer duration, and when moving at a fasterspeed, the location changes are determined at frequent time intervals.

In yet another aspect of the present invention, the positioning methodand frequency of location requests is adjusted based on batteryconstraints of the mobile device.

By reducing location requests or queries sent by the application(s) orthe mobile positioning system to the device, the invention enables sucha solution with significantly reduced power consumption requirements forthe GPS or A-GPS chipset embedded in the device, and reduces computingresource requirements in the mobile positioning system.

One aspect of the present invention is to determine the real-timelocation by maintaining a location profile of pre-determined locationsof a user and enabling power save modes when user is determined to be atthese locations. For instance, if a user is at their home or work, theembedded GPS or A-GPS chip can be set to sleep mode until the mobilepositioning system detects a change in location based on otherpositioning methods such as cell-ID and/or timing advance.

Another aspect of the present invention is for an application tosubscribe to a location server with user-controlled permissions in orderto receive real-time location updates of the user using a push-locationmethod, whereby the application receives location updates when theuser's location changes. Further, the application or the user mayspecify additional criteria that may limit or restrict when to enablelocation tracking or to send location updates to the application. Forexample, an enterprise application may only receive location updatespertaining to the specified places of work.

BRIEF DESCRIPTION OF THE DRAWINGS

Foregoing aspects of the present invention will become better understoodby referring to the following more detailed description and claims takenin conjunction with the accompanying drawings, wherein:

FIG. 1 is a block diagram of an exemplary pull-based location requestsystem;

FIG. 2 is a block diagram of an exemplary push-based real-time locationand mobile positioning system;

FIG. 3 is a block diagram of a push-client using motion and activitydetection methods on a device to manage a GPS Power-save mode;

FIG. 4 is a block diagram of the mobile positioning system using thepush-client and a push-server to determine a real-time location of thedevice and managing the GPS in a power-save-mode;

FIG. 5 is an overview of the push-client and the push-serverinter-process communication;

FIG. 6 is a block diagram of the push-client maintaining the real-timelocation as a user moves to an indoor environment where GPS signal maynot be available,

FIG. 7 is a block diagram of the push-client and the push-servermaintaining the real-time location and status of an user whileminimizing server updates and reducing network traffic; and

FIG. 8 is a block diagram of an exemplary system for detecting drivingstatus using “In Car” detection methods.

DETAILED DESCRIPTION OF THE EMBODIMENTS

FIG. 1 provides a general description of a pull-based location requestand response system 100, which is an overview of how the mobilepositioning systems currently operate. In such a system, an application110 requests location from a location server or a location middlewareprovider 108. The location middleware provider, in turn, requestslocation from the mobile positioning system, unless a current locationis available from another recent request. In the case of a GSM basedsystem, the mobile positioning system includes a Gateway Mobile LocationCenter (GMLC) 106 and a Serving Mobile Location Center (SMLC) 104, whichin case of a Global Positioning System (GPS) capable device, requestslocation from the mobile device 102, unless a request was recently madeby the system and a current location is already available in the mobilepositioning system. After a valid location is determined by the device102 that meets the accuracy criteria requested by the application 110,the location is sent to the SMLC 104, which further sends it to the GMLC106. The GMLC, if the application has met the credentials for accessingthe device's location, forwards the location to the location server ormiddleware provider 108, which then sends it the requesting application110. In the case of such a pull-based request and response system, alocation request has to be periodically made to refresh the currentlocation of the user.

In another implementation of such a pull-based location request andresponse system, an application 110 can request the location directlyfrom the GPS embedded in the mobile device 102, however, a location hasto be continuously and periodically determined by the GPS to maintain acurrent location of the user. Further, if the application 110 requiressuch a real-time location be maintained on a location server on anoperator or service provider network, such location updates have to becontinuously transmitted using the mobile network, and take up asignificant network traffic as well as drain the battery on the mobiledevice 102.

In another implementation of such a pull-based location request andresponse system, an application 110 can register with a locationlistener on the mobile device 102 that continuously requests locationfrom the GPS embedded in the mobile device 102, which may eliminate theneed for the application 110 to make such requests repeatedly, however,the listener is still periodically polling the GPS, and sending locationupdates to the subscribing application each time a location isdetermined by the GPS embedded in the mobile device 102.

FIG. 2 provides an overview of the push-based real-time location system200 proposed by the invention. In such an exemplary system, in additionto a standard mobile device 210 and a pull-based mobile positioningsystem 220 which was described in block diagram 100 earlier, the systemincludes a mobile device 230, push-based mobile location server (PMLS)240, an application server 250, and one or more real-time locationapplication(s) 260. The mobile device 230 includes a push-locationclient 232, an embedded GPS 234 and an embedded real-time locationapplication 236. The push-location client 232 manages the GPS 234 andmaintains the current location of the device, and provides locationupdates to the real-time location application 236, as well as to thepush-based mobile location server 240. The location server 240 canprovide location updates to subscribing application(s) such as real-timelocation application 260 either directly or through an applicationserver 250. The key advantage of this system is that a real-time or an“always-on” location application is not required to request or receivecontinuous location updates from the location server in order tomaintain the current location of the device, and instead locationupdates are sent the application intelligently when the locationchanges.

An exemplary real-time application 260 sends a subscription request withappropriate user-permissions and credentials, and the push-based mobilelocation server 250 first responds with the current location of thedevice, and subsequently sends location updates to the requestingapplication or middleware service provider as the location changes. Thereal-time application 260 or an embedded real-time application 236 arenot required to repeatedly send location refresh requests to the server250 or the GPS 234, and the push-location server similarly also doesn'tneed to send periodically repeated location refresh requests to thepush-client 232 embedded in the mobile device in order to maintain areal-time location of the device.

The push-location server 250 also maintains a profile of specified orpre-determined locations of the user, where the user is stationary for aspecified period of time. When the user is at these pre-determinedlocations, the push-location server 250 can optionally receive andmonitors cell-ID and timing advance information to detect a locationchange, and if a location is changed, and it hasn't received an updatefrom the push-client, it can then send a refresh request to thepush-client 232. During this time when the user is at thesepre-specified or per-determined locations, the push-client can send asleep command to the embedded GPS 234 for saving power consumption ofthe battery on the mobile device. When a location change is detectedeither by an activity detection method such as one described in blockdiagram 300, or by a notification from the push-server such as onedescribed in block diagram 400, the push-client 232 can wake up the GPSchip 234 and request a location update.

FIG. 3 is an exemplary block diagram of the push-client maintaining areal-time location of the device by monitoring when the device isstationary, and only when motion is detected, or a user activity isdetected on the device, a location refresh request is sent to theembedded GPS or A-GPS. In this exemplary implementation 300, in theblock 302, the Push-Client 232 sends a request to the accelerometerembedded in the device and/or to the mobile operating system to receivethe measurements from the accelerometer in order to determine motion ofthe device. In the decision block 304, when the device is considered tobe stationary, the Push-Client sends the command to put GPS in the powersave mode. If motion is detected, the Push-Client requests currentlocation and speed from the embedded GPS 234. In the block 310, thePush-Client 232 waits for specified time interval or in case ofaccelerometers or other motion detection methods that can provide eventtriggers when motion is detected, Push-Client 232 repeats the abovesteps. Further, the motion or activity of a mobile device 230 may bedetected by an accelerometer or other sensors embedded in the mobiledevice 230, or by other activity detection methods provided by themobile operating system. In an advanced implementation, this method maybe integrated within the GPS chip 230.

In another implementation, the GPS 234 may be embedded inside orintegrated with another chip inside the mobile device. In yet anotherimplementation, another global navigation satellite system (GNSS) suchas Galileo may be used for determining location, or a differentpositioning method, such as Wi-Fi based positioning method, used fordetermining location.

FIG. 4 is a more detailed flowchart of the push-based location systemdescribed in 200. In this implementation 400, in the block 402,Push-Client 232 requests location and speed from embedded GPS 234. Inthe decision block 404, when the device is determined to be stationaryat a pre-determined location within specified thresholds, in block 410,the Push-Client 232 puts GPS 234 in a power saving mode. Additionally,in the decision block 412, if it is determined that the location haschanged compared to last known location, in block 414, Push-Client 232sends a location update to Push-Server 240. If the location has notchanged in decision block 412, as well as after sending the update toPush-Server in case of block 414, in the block 416, the Push-Client 232,working in conjunction with the push-server to monitor and detect if thedevice location has changed, waits for notification from either themotion or activity detection methods as described in block diagram 300,or in case, such an option is not available, from the push-server 300indicating that the location may have changed.

When a notification or an event trigger is received, Push-Client 232wakes up the GPS 234, and requests a location update from the GPS as inblock 402. If in the decision block 404, the speed as determined by theGPS indicates that the device is in motion or at a new location, inblock 406, the Push-Client sends a location update to the server, andwaits for a specified time interval before requesting a location updatefrom the GPS 234. To further optimize the location updates betweenPush-Client 232 and Push-Server 240, and to reduce the network trafficas the location changes when the user is in motion or when the user isat a new location, the details of blocks 402, 404, 406, 408 and 412 arefurther described in block diagram 700.

When the device 230 is stationary at a pre-determined location, inblocks 418, 420, 422, and 424 the push-location server 240 periodicallyrequests and monitors cell-ID and timing advance information from themobile positioning system 220. If the location is determined to havechanged within specified thresholds, the push-location server sends arequest to the push-client 232 to send an updated location. Thepush-client 232 then wakes up the GPS or A-GPS chip 234, and refreshesthe current location.

When the push-client 232 requests location from the embedded GPS orA-GPS 234, it also requests the speed. If the device is considered to bemoving, it requests the location repeatedly to maintain a real-timelocation. The time for repeating the request when the device 230 is inmotion is calculated based on the speed of the device, such that a nearreal-time location is maintained by the push-client 232. When the deviceis determined to be stationary, the GPS 234 is sent the command to beput into a power-saving mode.

FIG. 5 is an exemplary description of the inter-process communicationbetween the push-client 502, and push-location-server 504 and anexemplary web based real-time application client 506, and applicationserver 508, and another exemplary embedded real-time mobile application510, such as a presence application, and a real-time application server512 such as a presence server. A push-client 502 sends a registrationrequest to the push-server, and sends the user's privacy settings to theserver. Once the registration is done, the current location is sent, andsubsequently location updates are sent to the push-server 504.

An exemplary web-based client application 506 and an application server508 can subscribe to receive real-time location updates from thePush-Location Server 504, with user-permission and based onuser-specified privacy settings. In the case of an exemplary embeddedmobile application 510, which is a real-time location based presenceapplication, the client application can subscribe to the Push-LocationServer, and receive location updates on the mobile device directly fromthe Push-Client, while the Application Server 512, a Presence Serverdetermines the presence status based on location profile, privacysettings, and location updates received from the push-location serverand the status updates received from the Presence Client 510. Thepresence status is then shared with other users based on the privacysettings with respect to each user.

FIG. 6 is a block diagram of a method used by the Push-Client 232 tomaintain a real-time location as a user moves to an indoor environmentwhere GPS signal may not be available. In this exemplary implementation600, Push-Client 232 requests location and speed from the embedded GPSin block 602, and as described earlier, in blocks 604, 606, and 608,sets the received GPS location as the current location if the user isdetermined to be stationary, and waits for specified time intervaland/or event triggers indicating that the user may have moved beforerequesting location from GPS again. In the decision block 604, if theuser is determined to be in motion, Push-Client 232 periodicallymonitors the location updates from the GPS 234, and if a valid locationupdate is received from the GPS 234, in block 622 it sets the newlocation as the current location. However, if in decision block 612, avalid location update is not received, as may be the case in an indoorlocation where GPS signal may not be available, in block 614,Push-Client 232 maintains the last known location as the currentlocation, and in block 616, requests location from other indoorpositioning modes, such as WiFi based location to monitor changes tolast known location. In such a case, often the GPS may take longer todetermine location or may not receive the location depending on theindoor environment. In block 618, the Push-Client waits for specifiedtime interval, and if valid location is received, in block 620 and 622,it updates the current location, and until a GPS location is received itmaintains the last known location as the current location.

FIG. 7 is a block diagram of the push-client and server maintaining areal-time location and status of user while minimizing server updatesand reducing network traffic. In the block diagram 700, as describedearlier in block diagram 400, in block 702, when the Push-Client 232receives a new location update from the GPS 234, it determines if thelocation has changed, and if it is a distinct new location compared tolast known location. In order to determine this, in block 704, itcalculates distance between the new location and previously savedlocation. If in the decision block 706, the distance is greater than theminimum specified threshold for determining a distinct location, then inblock 708, the Push-Client 232 saves it as the current location of theuser.

In decision block 710, a determination is made if the speed is above thespecified threshold for the user to be considered driving or in transit,and further, additional methods may be used to determine the drivingstatus of the user, as described later in block diagram 800. If the useris determined to be in transit or driving, a transit message is sent tothe Push-Server 240. Subsequently, in block 714, the Push-Client 232periodically monitors the location and speed at specified timeintervals, and saves the current location of the user, and periodicallysends location updates to the Push-Server 240 so the server can maintaina real-time location of the user. In another implementation, thePush-Client 232 may only send the transit start and end points to theserver to reduce the network traffic, and in yet another implementation,the Push-Client may intelligently determine when the heading or speedchanges more than specified thresholds, and thereby only sendinglocation updates when street information has likely changed, or whencurrent location can't be interpolated by the server.

In decision block 716, if it is determined that the user is nowconsidered stationary, in decision block 718, it is further determinedif the user is at a pre-determined or a favorite location. If the useris at such a location, the corresponding favorite location and statusupdate is sent to the Push-Server 240. However, if in decision block718, user is determined to be at a new location, Push-Client 232 sends alocation update to the Push-Server 240, and a corresponding address orPOI information is determined by the server based on reverse geocode andPOI search APIs. Subsequently, in block 726, the Push-Client 232 waitsfor specified time interval and/or event triggers indicating the usermay have moved before requesting another update from the GPS 234.

FIG. 8 is a block diagram of an exemplary system for detecting drivingstatus using “In Car” detection methods. In block diagram 800, inaddition to determining transit status based on the speed threshold asdescribed earlier and here again in blocks 802, 804 and 806, additional“In Car” methods may be used for detecting the driving status. Indecision block 808, if an “In Car” method is enabled, the detection testis started in block 810. In one implementation, a proximity sensor maybe used inside the car to detect the mobile device is inside the car. Inthe decision block 812, if a proximity sensor based detection method isavailable and enabled, in block 814, it is used to determine the “InCar” mode. In another implementation, connectivity status to an “In Car”accessory may be used for driving detection, as described in blocks 816and 818. Additionally, if a user is determined to be in transit, and thedevice has a Bluetooth “In Car” profile setup, connection can beestablished using the Bluetooth profile to enable the driving profile asdescribed in blocks 820 and 822. If the driving status is detected inblocks 814, 818, or 822, or assumed as the default option in block 806,the driving status is set and a corresponding transit update sent to thePush-Server 240. In another implementation, user can optionally specifythe mode of transit, which is used as a default option when the user isdetermined to be in transit based on the speed threshold.

The invention claimed is:
 1. A computer-implemented method, comprising:determining, by a mobile device, a current location of the mobile devicefrom a mobile positioning system associated with the mobile device;determining, by the mobile device, whether the mobile device has changedlocation based on motion or event triggers from a motion detectionsystem, wherein the motion detection system provides motion or eventtriggers when a position of the mobile device has changed; determining,by the mobile device, whether the location of the mobile device haschanged and the mobile device is stationary based on data from a motiondetection system of the mobile device, wherein the determination ofwhether the location of the mobile device has changed and whether themobile device is stationary do not occur at the same time; when themobile device is determined not to have changed location, putting themobile positioning system into a power-saving mode; and when the mobiledevice is determined to have changed location: activating, by the mobiledevice, the mobile positioning system, and determining, by the mobiledevice, the location of the mobile device from the mobile positioningsystem to maintain an accurate location of the mobile device.
 2. Thecomputer implemented method of claim 1, wherein the motion detectionsystem comprises an accelerometer and the mobile device is configured todetermine whether the location of the mobile device has changed or themobile device is stationary based on data from the accelerometer.
 3. Thecomputer-implemented method of claim 1, further comprising: providing,by the motion detection system, event triggers to the mobile device whenthe motion detection system determines that the mobile device haschanged location, is stationary, or is in motion or activity states. 4.The computer-implemented method of claim 3, wherein the mobile device isconfigured to manage the power-saving mode based on the event triggersfrom the motion detection system when the mobile device has changedlocation, is stationary, or is in motion or activity states.
 5. Thecomputer-implemented method of claim 1, wherein the mobile device isconfigured to determine whether the position of the mobile device haschanged using activity detection of the mobile device.
 6. Thecomputer-implemented method of claim 5, wherein the activity detectioncomprises determining whether the mobile device is stationary, inmotion, or driving in a vehicle.
 7. The computer-implemented method ofclaim 1, wherein when the mobile device is determined to be at an indoorlocation, the method further comprises: determining, by the mobiledevice, whether the location changed using an indoor positioning mode todetermine the current location of the mobile device.
 8. Thecomputer-implemented method of claim 1, further comprising: initiatingthe power-saving mode, by the mobile device, when the mobile positioningsystem is not in the power-saving mode and the mobile device isdetermined not to have changed location for a specified period of time.9. The computer-implemented method of claim 1, wherein the determiningof whether the location of the mobile device has changed comprises:using information associated with signals received by the mobile device;and monitoring for changes in the signals to detect whether the locationof the mobile device has changed.
 10. A computer-implemented method,comprising: detecting, by a mobile device, whether a location of themobile device has changed by using information associated with signalsreceived by the mobile device; when the location of the mobile devicehas changed, activating, by the mobile device, a mobile positioningsystem, and determining, by the mobile device, a current location of themobile device from the mobile positioning system to maintain the currentlocation of the mobile device; and when the location of the mobiledevice has not changed based on changes in signals received abovespecified thresholds, putting receive circuitry of a global positioningsystem (GPS) in standby mode, and shutting down other power-consumingcircuits of the GPS system, wherein the detection of whether thelocation of the mobile device has changed further comprises monitoringfor changes in the signals to detect whether the location of the mobiledevice has changed.
 11. The computer-implemented method of claim 10,wherein the information comprises an identifier of a cellular basestation or another transmitting device associated with the signalsreceived by the mobile device.
 12. The computer-implemented method ofclaim 10, wherein the information comprises timing advance, signalstrength, or both, of the signal.
 13. The computer-implemented method ofclaim 10, further comprising: providing, by the motion detection system,event triggers to the mobile device when the motion detection systemdetermines that the mobile device has changed position.
 14. Thecomputer-implemented method of claim 13, wherein the mobile device isconfigured to manage the power-saving mode based on the event triggersfrom the motion detection system when the mobile device has changedposition.
 15. The computer-implemented method of claim 10, wherein whenthe mobile device is determined to be at an indoor location, the methodfurther comprises: determining by the mobile device, whether thelocation changed using an indoor positioning mode to determine anaccurate location of the mobile device.
 16. The computer-implementedmethod of claim 10, further comprising: initiating a power-saving mode,by the mobile device, when the mobile device is determined not to havechanged location for a specified period of time.
 17. Acomputer-implemented method, comprising: determining, by a mobiledevice, a current location of the mobile device from a mobilepositioning system associated with the mobile device; when a globalpositioning system (GPS) is unavailable, determining, by a mobiledevice, whether the mobile device is at an indoor location using Wi-Fior Bluetooth indoor positioning and associating the current or a lastknown location with the indoor location; when the mobile device isdetermined to be at the indoor location, putting the mobile positioningsystem into a power-saving mode and using the Wi-Fi or Bluetooth indoorpositioning to determine the location of the mobile device; receiving,by the mobile device, location updates from a motion detection system;determining a current location of the mobile device based on thereceived location updates from the motion detection system until GPSposition information is available; and when the mobile device isdetermined to have changed location and is no longer at the indoorlocation, activating, by the mobile device, the mobile positioningsystem, and determining, by the mobile device, the location of themobile device from the mobile positioning system to maintain the currentlocation of the mobile device.
 18. The computer-implemented method ofclaim 17, wherein the indoor positioning comprises using a globalpositioning system (GPS), cellular signals, Wi-Fi, Bluetooth, or anycombination thereof to determine whether the mobile device is at theindoor location and to maintain a real-time location of the mobiledevice.
 19. The computer-implemented method of claim 17, wherein whenthe mobile device is determined to be at the indoor location, theputting the mobile positioning system into the power-saving mode furthercomprises putting the mobile positioning system into the power-savingmode such that GPS is not used and there is no GPS tracking while themobile device is in the indoor location.